Control unit for motors with belt drives



Nov. 7, 1950 P. F. CRATON 2,528,581

CONTROL UNIT FOR MOTORS WITH BELT DRIVES Filed Dec. 2, 1948 Frail.

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Am F. 6734 7pm Patented Nov. 7, 1950 UNITED STATES PATENT OFFICE CONTROL UNIT FOR MGTORS WITH BELT DRIVES 2 Claims.

This invention relates to a control unit where by a motor may be stopped if its belt drive becomes badly worn or is about to break.

An object of my invention is to provide a novel control unit including a switch which is placed adjacent the belt drive of a motor, the control unit being actuated if the belt frays or breaks.

Another object of my invention is to provide a novel control unit of the character stated,

which requires no change in the motor drive but which is mounted adjacent the belt drive of the motor and is actuated by the broken strands of the belt as said belt rotates.

Another object of my invention is to provide a novel control unit of the character stated, which is simple in construction, inexpensive to manufacture, and effective in operation.

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

In the drawing:

Figure 1 is a diagrammatic side elevation of a motor drive with my control unit mounted adjacent thereto. 7

Figure 2 is a side elevation of my control unit with parts broken away to show interior construction.

Figure 3 is an end view of my control unit.

Referring more particularly to the drawing, my control unit I is associated with a motor 2, which drives a shaft 3 through the medium of a belt or belts 4, which travel over pulleys 5-6.

The belt or belts 4, when they are about to break or are badly worn, will fray and these frayed ends will extend away from the surface of the belt due to the rotation of the pulleys and these frayed strands actuate my control unit I, as will be more specifically described.

The control unit I consists of a box or housing 1, which is fixedly mounted to a suitable post or the like 8 by means of the studs 9. The housing 1 is preferably mounted adjacent pulley 5 and this pulley is rotating in the direction shown by arrow in Figure 1.

A cover plate Illcloses the top of the housing 1 and a precision switch II is mounted in this cover plate. The precision switch is a type of electrical switch requiring a very small throw in order to open or close an electrical contact. The conduits l2, extending from the switch I I to the motor or other power means 2 and when the precision switch II is open current is broken to the motor and the motor will stop.

The switch II is actuated in the following manner: a ridged bar I3 is suspended above the switch I I and just clears this switch so that any slight downward movement of the bar I3 will cause the switch I I to be engaged and actuated. A pair of spring fingers I4-I5 are fixedly attached at one end to the bar I3. The tension of the spring fingers I4I5 is sufiicient to nor mally hold the bar I3 immediately above the switch 11. If the belt 4 should fray, as will happen when the belt is about to break, the frayed ends of the belt will stand out tangentially from the pulley 5 and will strike the bar I3 causing the bar to be thrown downwardly engaging the switch I I and causing this switch to open its contact, the motor 2 will then stop and the belt 4 can be replaced.

Having described my invention, I claim:

1. A control unit for motors with belt drives comprising a housing, means mounting said housing adjacent the belt, a motor control switch mounted in said housing, a bar mounted on the housing above said switch and engageable therewith to actuate the switch, said bar being adapted to be struck by any protuberance on the belt, and a spring finger mounted at one end on the housing and at the other end on said bar.

2. A control unit for motors with belt drives comprising a housing, means mounting said housing adjacent the belt, a precision switch mounted in said housing and protruding through the top thereof, said switch being adapted to control a motor, a bar mounted on said housing for vertical movement and positioned above said switch and engageable with the switch to actuate the same, said bar being adapted to be struck by any protuberance on the belt, and a spring finger mounted on one end at the housing and at the other end on said bar.

PAUL F. CRATON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,139,839 Bottinelli May 18, 1915 2,444,170 Sahel et a1. June 29, 1948 

